Filtered cigarettes are well-known and are a common form of smoking articles. Filtered cigarettes comprise a column of tobacco and, at one end, a filter plug (i.e., a filter). The column of tobacco is wrapped in cigarette paper and the filter plug is joined to the cigarette by tipping paper. Conventional filters are formed either from compressed strips of paper or cellulose acetate tows. However, thermoplastic polymers possess attributes that would suggest they might be converted into materials that could be used as cigarette filters. For example, U.S. Pat. No. 3,595,245 issued to Bunt et al is directed to a meltblown roving of polypropylene fibers formed as a tow and processed into cigarette filters. Also, U.S. Pat. No. 4,546,040 issued to Knotek et al describes other polypropylene filter cigarette filters. Such thermoplastic polymer filament filters, such as those made of polypropylene fibers have achieved little, if any, commercial success. Common deficiencies of such attempts to form thermoplastic filament filters have included inadequate firmness so that the filter end of the cigarette has an uncharacteristic and undesirable softness. Other deficiencies include a greater than desired pressure drop so that the smoker experiences a perceivable increase in draw resistance.
Accordingly, there is a need in the industry for a filter for smoking articles made from a web of synthetic fibers that overcomes the deficiencies present in filters made from previously known thermoplastic and nonwoven filament webs.